RT Journal Article
SR Electronic
T1 Neuroimaging activation studies in the vegetative state: predictors of recovery?
JF Clinical Medicine
JO Clin Med
FD Royal College of Physicians
SP 502
OP 507
DO 10.7861/clinmedicine.8-5-502
VO 8
IS 5
A1 Haibo Di
A1 Melanie Boly
A1 Xuchu Weng
A1 Didier Ledoux
A1 Steven Laureys
YR 2008
UL http://www.rcpjournals.org/content/8/5/502.abstract
AB The vegetative state (VS) is a devastating clinical condition characterised by wakefulness without awareness. Functional neuroimaging permits to objectively measure brain responsiveness to external stimuli in VS. The literature on functional magnetic resonance imaging and positron emission tomography studies in these patients has been reviewed. Results from 15 studies were classified in: absent cortical activation or ‘typical’ activation of ‘low level’ primary sensory cortices and ‘atypical’ activation spreading to ‘higher level’ associative cortices. This descriptive review on 48 published cases suggests that ‘atypical’ activation patterns seem to herald recovery from VS with a 93% specificity and 69% sensitivity. Passive stimulation paradigms, however, do not permit to make strong claims about the absence or presence of consciousness. Recently proposed mental imagery paradigms permit to identify signs of consciousness in non-communicative brain damaged patients. The clinical application of these functional neuroimaging techniques awaits validation from ongoing multi-centric cohort studies in these challenging patients with chronic disorders of consciousness.